What does it mean that the body is sown natural and raised spiritual?
The natural body is the one born of the flesh, sown in death; the spiritual body is raised by resurrection power with the Spirit as its life source. It keeps outward features but possesses eternal life rather than the ordinary lifespan, entering eternity as flesh and bone, not flesh and blood.
Les teaches that the body sown natural is that which was born of the flesh. That body of flesh has to die and then be raised in resurrection power. If believers do not live to see the rapture and go by way of death, they have the blessed hope that the body will be raised a new life. The resurrection body is spiritual: believers will not go into eternity in flesh and blood, but in flesh and bone, with the Spirit as their life source. Paul says there is a natural body and a spiritual body. Even though they are eons apart, they are a lot alike, because the outward features remain; the difference is that the spiritual body has eternal life instead of the promised three score and ten. Verse 45 also contrasts the first Adam, who was made a living soul, with the last Adam, the second Adam.
It is sown a natural body; it is raised a spiritual body. There is a natural body, and there is a spiritual body.